Ignition Problems on 86 Jeep CJ7 No Spark From Coil??

So I have replaced the control module, starter solenoid, and coil and still no spark from the coil to the negative terminal for testing. I was told it should spark 6 times for every revolution and it will only spark once if at all. I checked the voltage and it was good (around 6v) when key is on but when cranking it is only around 8.8V and should be near 12V. I believe the resistance wire could be the problem. It says it should be 1.35 ohms and I found it around 1.8 ohms so it seems like it must be partly broken somewhere. Can I just jump 12V from the battery to the coil to check this or can it damage something?

I have 85 cj7 with no spark to plugs...replaced cap, wires, plugs, coil and igntion control module. starter works fine and motor turns over fine. Jeep was running before these changes. Wires are on the correct plugs. I have tested for fire coming out of distributor and do not have any.I have 85 cj7 with no spark to plugs...replaced cap, wires, plugs, coil and igntion control module. starter works fine and motor turns over fine. Jeep was running before these changes. Wires are on the correct plugs. I have tested for fire coming out of distributor and do not have any.

AnonymousMay 06, 2009

I get 1 spark when the ignition is turned off. No spark while cranking. I went through the book and no problem found. coil , module, and voltage all ok I get 1 spark when the ignition is turned off. No spark while cranking. I went through the book and no problem found. coil , module, and voltage all ok

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Check the battery terminals,and battery posts, they may need to be cleaned. Your local parts store sells a battery post and terminal cleaner brush. When disconnecting the battery besure not to cause any sparks and if you smoke put it out before starting any battery maintence. Take the negative terminal off first, clean but dont put it back on yet. take the positive terminal of and clean both the terminal and the battery post.. Have someone with a volt meter check the voltage in the battery, if it measures 12volts, if available, then install the positive terminal first, then the negative post last taking care not to create any sparks. Once that is done try to start the car. If it starts, you have fixed it. If not, then you will have to move on to the starter solenoid.on the left inner fender, the other end of the positive batery terminal cable hooks to it. Again take the negative battery terminal off and replace the solenoid. Pay close attention where the wires came off of. Once you have replaces the solenoid, hook the negative terminal back on to the battery. This should take care of the problem, If not then you have to take the starter off and take it to you local parts store and have it tested they will tell you if it is bad. That is the last thing in the starting circuit that will cause the clicking noise. I hope this information help you to sovle you problem.

An ignition switch supplies voltage to the ignition control module and/or the ignition coil. Often an ignition sytem thas two wires connected to the run terminal of the ignition switch. On is connected to the module. The other is connected to the primary resistor and coil. The start terminal of the switch is also wired to the module.
You can check for voltage using either a 12-volt test light or a digital multimeter (dmm).
To use a test light:

Turn the ignition key off and disconnect the wire connector at the module.

Disconnect the S terminal of the starter solenoid to prevent the engine from cranking when the ignition is in the run position.

Turn the key to the run position and probe the red wire connection to check for voltage.

Check for voltage at the battery terminal of the ignition coil using the test light.

Next, turn the key to the start position and check for voltage at the white wire connector at the module and the battery terminal of the ignition coil. If voltage is present, the switch and its circuit are okay.

To do the same test using a DMM:

Turn the ignition switch to the off position and back-probe, with the meter's positive lead, the power feed wire at the module.

Connect the meter's negative to a good ground at the distributor base.

Turn the ignition to the run or start position as needed, and measure the voltage.

The "Checking For Spark'' test should be performed prior to this test.

This is a basic test of the ignition system that
systematically examines the battery, the coil, the engine controller,
and its wiring harness and connections; the most likely culprits in a
no-start condition at this stage.

Fabricate this special jumper with a 0.33 MF capacitor in-line to test the ignition coil
Click to Enlarge

Unplug the ignition coil harness connector at the coil.

Connect a set of small jumper wires (18 gauge or smaller) between
the disconnected harness terminals and the ignition coil terminals.

Attach one lead of a a voltmeter to the positive (12V) jumper
wire. Attach the negative side of the voltmeter to a good ground.
Measure the voltage at the battery and confirm that enough current is
available to operate the starting and ignition systems.

Crank the engine for five seconds while monitoring the voltage at the coil positive terminal:

If the voltage remains at zero, diagnosis of the fuel system
should be performed. Also check the engine controller and auto shutdown
relay.

If voltage is at or near battery voltage and then drops to
zero after one or two seconds of engine cranking, check the engine
control module circuit.

WARNING

The ignition must be turned OFF prior
to unplugging the engine controller connector. If it is not, electrical
surging could occur causing damage to the unit or other electrical
components in the vehicle.

If the voltage remains at or near battery voltage during the entire five seconds, turn the ignition key OFF.
Remove the 14-way connector on 1989 models, or the 60-way connector on
1990-96 models at the engine controller. Check the 14-way or 60-way
connector for any spread terminals.

Remove the test lead from the coil positive terminal. Connect an
18 gauge jumper wire between the battery positive terminal and the coil
positive terminal.

Make a special jumper cable (see illustration). Using the jumper
MOMENTARILY ground terminal 12 on the 14-way connector (1989), or
terminal 19 (see illustration) of the 1990-96 60-way connector. A spark
should be generated at the coil wire when the ground is removed.

If a spark is generated, replace the engine controller computer.

If no spark is seen, use the special jumper to ground the
coil negative terminal directly. If spark is produced, repair the wiring
harness for an open circuit condition. If spark is not produced,
replace the ignition coil

this is for distributor ignition

THIS IS TESTING OF DISTRIBUTORLESS IGN
Testing

This procedure requires an ohmmeter to test the coil
packs for primary and secondary resistance (specifications are given
for an ambient temperature of 70-80°F/21-27°C).

Check the secondary resistance of each individual paired coil by
connecting an ohmmeter across the coil towers. This must be done between
the correct cylinder pairs: 3/2, 7/4, 1/6, 9/8, or 5/10. Resistance for
a Diamond coil should be 11,300-15,300 ohms. For a Toyodenso
manufactured coil pack, resistance should be 11,300-13,300 ohms.

Use an ohmmeter to check secondary resistance as shown

Check the primary resistance of the front coil pack by attaching
an ohmmeter between the B+ coil terminal and either the right (cylinders
3/2), center (cylinder 7/4), or left coil (cylinders 1/6) terminals.
Resistance for a Diamond coil should be 0.97-1.18 ohms. Resistance for a
Toyodenso coil should be 0.95-1.20 ohms.

To test the primary resistance of the rear coil pack, attach an
ohmmeter between the B+ coil terminal (see illustration) and either the
right (cylinders 9/8), or left (cylinders 5/10) coil terminals.
Resistance for a Diamond coil should be 0.97-1.18 ohms. Resistance for a
Toyodenso coil should be 0.95-1.20 ohms.

i hope this helps any more questions repl if help at all plz vote or comment me

Cap, rotor, wires, plugs... for starters (no pun) I assume you're not getting spark. Other possibilities ignition switch or small leads on solenoid. Did you disconnect your battery when installing module. There's a possibility if you did not that it shorted (power surge) when you plugged it in. They were very sensitive back then. The correct way WHENEVER you disconnect battery is positive first, negative ALWAYS last.

TESTING WARNING During the following test, the starter motor must not be energized for longer than 5 seconds, otherwise you run the risk of burning out the starter motor coil.

Remove the starter motor from the vehicle.

Detach the field coil lead from terminal M on the starter motor.

Using jumper wires, connect a 12 volt battery to the starter motor so that the negative battery terminal is attached to the starter motor housing and to solenoid terminal M, and that the positive battery terminal is connected to starter motor solenoid terminal S. The starter motor plunger should move outward; if it does not, replace the solenoid with a new one.
Fig. 1: To test the solenoid plunger, first detach the field coil lead from alternator terminal M, then attach a 12 volt battery to the starter motor as shown . . .
Fig. 2: . . . then detach the negative jumper wire from terminal M. The plunger should remain extended
Fig. 3: Detach the other negative lead from the starter motor housing. The solenoid plunger should now retract to its normal resting position
Fig. 4: Use an ammeter to measure the amount of current draw the starter motor uses

Detach the negative battery jumper wire from terminal M on the starter motor solenoid, and check the plunger for movement. The plunger should remain extended; if the plunger returns to its resting position, replace the solenoid with a new one.

While observing the solenoid plunger, detach the negative battery lead from the starter motor housing. The plunger should return to its normal resting position; if it does not, replace the solenoid with a new one.

Reattach the 12 volt battery and install an ammeter to the starter motor as shown in the accompanying illustration. The starter motor should rotate smoothly and steadily with the pinion gear moving out, and the ammeter should display less than 60 amps at 11.5 volts (Samurai models), or 90 amps at 11 volts (Sidekick, Tracker, X-90 and Sidekick Sport models). If the ammeter does not display the specified values, or if the starter motor does not operate smoothly and steadily, replace the starter motor with a new one.

If necessary for added under-vehicle clearance, apply the parking brake, block the rear wheels, then raise and safely support the front of the vehicle on jackstands.

From beneath the vehicle, label and detach all wiring from the starter motor solenoid terminals.

Remove one of the two starter motor mounting bolts and loosen the other bolt until it can be turned by hand, then support the starter motor with one hand while removing the last starter motor mounting bolt.

Lower the starter motor down and away from the engine and transmission.
To install:

Hold the starter motor in position and install the two mounting bolts. Tighten the two bolts securely.

Reattach all applicable wiring to the starter motor solenoid. Ensure that the wiring terminals and connectors are clean and free of corrosion.

Check for 12 volts to ignition module from ignition switch, with a test light.Don't replace things like coil or distributor, but instead just have them checked at a parts place.Could not possibly be starter solenoid, but could be wiring at starter or ballast resistor.

Ignition Module is actually a class C amplifier. It amplify signal instead of music. Class C amplifier are very efficient type of ampifier. They are used to drive the flyback transformers in a television to create high voltage for the screen. In a car it drives the ignition coil to produce high voltage for the spark plug.
You can't test them unless you know electronics, but you can do an elimination process. Remove the ignition coil from the car, and bench test it. Note the postive and negative terminals. connect a spark plug to the output. and ground the spark plug at the negative side of the two terminals. Apply 12 volts to the terminal, then take off the positive side, as the voltage collapses a high voltage is induce firing the spark plug. The most likely item to go bad in an ignition system is the coil or the ignition module since they work the hardest. If the coil tested good you are almost sure it is the module.